Radiosonde balloon breakage switch



June 19, 1956 E. A. TERHUNE 2,751,456

RADIOSONDE BALLOON BREAKAGE SWITCH Filed Dec. 31, 1952 EDGAR A. TERHUNE BY x &

United States Pamr RADHOSONDE BALLOON BREAKAGE SWITCH Edgar A. Terhune, Little Silver, N. l, assigno'rto the United States of America asrepres'ented by the Secretary of the Army Application December 31, 1952,-Serial No. 322,158

Claims. (Cl. ZOO- 81) (Granted under Title 35, U. S. Code'(1-952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

The present invention relates to an electrical switching device for use in meteorological equipment carried aloft by a balloon or a cluster of balloons.

More specifically the invention is concerned primarily with a switching device that will resolve the exact breaking time of either a single balloon in individual flight, or in a cluster of balloons, upon reaching maximum altitude.

A primary object of the invention is to provide a switching device which functions independently of any outside means.

Another object of the invention is to provide a means for determining the breakage time of a balloon in flight.

Another object of the invention is to provide a switching device that is of light weight and has relatively few parts whereby it can be inexpensively made.

These and other objects are attained by providing a switching device secured to the balloon which is actuated upon the collapse of the balloon as hereinafter described.

The invention can best be understood from the following description to be read in conjunction with the drawing in which:

Figure l is a perspective view of the complete assembly,

of a meteorological balloon in flight, its switch control assembly and associated radiosonde equipment;

Figure 2 is a view in perspective of the switch control device;

Figure 3 is an elevational view of the switch control device in closed or operative position, the plate being partly cut away to reveal the switch;

Figure 4 is an elevational view showing the switch device on the balloon and in closed position, when the balloon is fully inflated;

Figure 5 is an elevational view of the balloon upon collapse with the switch in open or inoperative position; and

Figure 6 is an elevational view of a modification of the invention showing another means of holding the switch control device.

For convenience of description, that portion of the balloon from which the neck portion extends, will be hereinafter described as the base of the balloon, and the re mote or opposite side as the top of the balloon.

Referring to the drawing, there is shown a rubber balloon 11 having an extended neck portion 13. The switch control device generally designated as is so designed so as to fit over the neck 13 of the balloon. The switch device 15 comprises essentially a substantially triangular plate 17 having a central circular opening 19. The plate 17 is also provided with openings 21, located at each of its corners. The plate 17 is further provided with flanges 23, each of which extends downwardly in a right angle direction from the surface of the plate. Secured to one of the flanges, and extending partly through an opening 24 in plate 17, is a switch 25 incorporating as Patented June 19, 1956 ICC one of its components a flat metallic spring finger 27 which when pressed, or in operative position, lies in a plane parallel to the plate 17. The switch 25 is of conventional commercial manufacture and of the type where the switch is closed or in operative position when the control finger is substantially flush with the plate 17 and the circuit open or inoperative when one end of the finger 27 is spaced away from the plate. One of such typical switches is a single pole, double throw, sub-miniature microswitch manufactured by the Minneapolis-Honeywell Regulator Company.

Extending through the plate 17 are three bolts 33, which serve in conjunction with nuts 34, as a means for loosely securing a ring 29. The ring 29 has a central opening-31 and three smaller openings 32 through which the bolts 33 extend. As the bolts 33 are of length greater than the thickness of the ring 29, the plate 17 and the ring 29 can be spaced from each other as shown in Figure 5. Surrounding each bolt, and within each opening 32 is a spring 35 which normally tends to urge the ring 29 away from the plate 17. In the embodiment illustrated in the drawings, the ring 29 is shown as made of a clear transparent plastic, so that in several of the views, various parts of the switch are readily seen.

For fastening the switch control device 15 to the balloon, three short straps 37 made of elastic webbing or rubber are provided. Each strap 37 is secured in identical manner, i. e., one end of a strap is secured to one corner of the plate 17, through the opening 21, while the other end is secured to the balloon by a vulcanized patch 39. The straps 37 are secured to the balloon at points equally spaced from each other. The length of each of the straps 37 is such that when the balloon is fully inflated there will be no slack in the straps. The straps should be of a material that has a greater degree of elasticity, and of greater tensile strength than that of the balloon material for reasons hereinafter set forth. As shown in Figure 4, when the balloon is fully inflated, the pull of the straps 37 will be strong enough to overcome the pressure of the springs 35 whereby the base plate 17 and the ring 29 will be in intimate face to face contact. When the base plate 17 and the ring 29 are so positioned the finger 27 will be depressed and be flush with the plate 17, and in such position the circuit is closed.

Secured to the neck 13 of the balloon is a cord 41, which in turn supports a housing 43 in which the radiosonde equipment is contained. A conductor 45, of two coil wire, coiled about the cord 41 electrically connects the switching device 25 to the rediosonde equipment.

Figures 4 and 5 portray the banner in which the switch device 15 functions. As set forth above, Figure 4 shows the balloon inflated and in such condition, the plate 17 and ring 29 are in contact thereby depressing the finger 27 and closing the electrical circuit. At the moment the balloon reaches its flight Zenith, that is, when the material of the balloon will burst, the balloon will col lapse as shown in Figure 5. At such time the straps 37 will fall slack and the springs 35 will urge the plate 17 and ring 29 apart. At that moment the finger 27 will spring upwardly opening the circuit to the transmitting equipment in the housing 43. Inasmuch as the straps 37 are made of a material that is more elastic and has a greater tensile strength than the balloon itself, no rupturing or breaking 'of the straps will take place. Batteries contained within the housing 43 are used to supply the current needed for the functioning of the radiosonde equipment.

In Figure 6, there is shown a modification of the invention, specifically the means of holding the switch device 15. In lieu of the straps 37, there are provided a plurality of engirdling bands 47. One end of each of the bands 47 is secured to the plate 17, While its other end terminates at the top of the balloon in a bridle-like device (not shown). Upon collapse of the balloon, the bands will slacken and the switch device will function as hereinbefore set forth.

While there have been herein described the preferred forms of the invention, it is obvious that changes and deviations may be made therefrom without departing from the spirit and scope of the following appended claims.

What is claimed is:

1. A device for determining the breaking time of a balloon or the like comprising discrete juxtaposed plate members secured to said balloon, means to normally urge said plate members apart, a switch operably associated with said plate members, means intermediate one of said plate members and said balloon to urge said plates into intimate contact with each other only when said balloon is inflated and a finger between said plate members for actuating said switch whereby when said plates are in intimate engagement said switch is operative and inoperative when said plates are spaced from each other.

2. A device of the kind set forth in claim 1 wherein the means for urging said plate members apart comprise a plurality of springs between said plate members.

3. A switching device of the kind set forth in claim 1 and further provided with a transmitting means actuated by said switch.

4. A device for determining the breaking time of a balloon or the like comprising discrete juxtaposed plate members secured to said balloon, spring means to normally urge said plate members apart, a switch operably associated with said plate members, a finger between said plate members for actuating said switch whereby said switch is operative when said plates are in intimate contact and inoperativewhen said plates are spaced from each other, and means comprising a plurality of elastic straps extending from one of said plates to said balloon to urge said plates into intimate contact when said balloon is inflated, and maintain said switch operative, and when the balloon is deflated and the straps are slack the plates are urged apart by said spring means to maintain the switch inoperative.

5. A switching device of the kind set forth in claim 4 and further provided with a transmitting means actuated by said switch.

References Cited in the file of this patent UNITED STATES PATENTS 1,769,427 Garside July 1, 1930 2,399,168 Cranmer Apr. 30, 1946 2,520,241 Geraci et a1 Aug. 29, 1950 2,545,248 Winzen et al Mar. 13, 1951 2,550,986 Flanery et al May 1, 1951 

